Planetary transmissions are typically designed to provide multiple speed ranges while remaining compact and power dense. In off-highway equipment, there is often a need to have an output from the transmission that can be applied to both front and rear wheel drive axles. This is usually accomplished with a drop gear train that leads to an output shaft. Trying to mate gearing of a planetary gear set with gearing of an input shaft of a drop gear train in an efficient special manner is difficult.
High speed planetary transmissions typically have trouble with noise, vibration and harshness (NVH). One method to help reduce NVH is to dynamically balance high speed components of these transmissions. Balancing of these high speed components can be difficult due to the manner in which these components interface with each other.
An accurate setting of taper roller bearings is critical to maximizing the fatigue life of the bearings and to provide proper shaft dynamic stability. Complicated and capital intensive tooling is often required to provide an arrangement adequate for setting the bearings.